基于改进拟动力法的主动土压力分析研究

地震条件下土压力的获取在目前的研究中通常采用拟动力方法,此方法往往忽略了后填土介质的粘弹特性及自由表面零应力这个边界条件。为了弥补现有拟动力方法的不足,考虑地震波传播介质的粘弹特性,改进原有的拟动力法;进而推求含有超载角的倾斜挡墙的主动土压力及其临界破坏时的破裂角计算公式,分析了超载角、地震力系数等参数对临界破裂角及主动土压力系数的影响。结果表明:临界破裂角随竖直地震力系数的增大而增大;水平地震力系数、超载角、内摩擦角以及挡土墙倾角对挡土墙设计影响大。

Active earth pressure of retaining wall based on modified pseudo-dynamic method

The pseudo dynamic method is one of the most common methods to obtain the earth pressure under seismic conditions. However, this method often ignores the viscoelastic characteristics of the backfill medium and boundary condition with the zero stress on the free surface. In order to remedy the deficiency of the existing pseudo dynamic method, in this paper, the viscoelastic properties of seismic wave propagating medium are considered to improve original pseudo-dynamic methods; Then the calculation formula of the active earth pressure of the inclined retaining wall with overload angle and the fracture angle under the critical failure are derived, and the influences of overloading angle, seismic force coefficient and other parameters on the critical rupture angle and the coefficient of active earth pressure are analyzed. The results show that the critical rupture angle increases with the increase of vertical seismic force coefficient; the horizontal earthquake force coefficient, overloading angle, internal friction angle and retaining wall inclination have great influence on the design of retaining wall.